The invention disclosed herein relates generally to cooking appliances, and more particularly to a cowling operable in an electric self-cleaning cooking appliance and a method for influencing a property of the air via which convection heating of an oven cavity of an electric self-cleaning cooking appliance is effected.
Substances baked or broiled inside an oven may generate materials, such as, for example, grease, which over time may become undesirably deposited as cooking food residues or deposits on the walls defining the heated space of an oven, stove, or range (hereinafter “ovens” for simplicity) and/or any apparatuses deployed within the heated space such as, for example, a broiling tray. One type of oven, such as is disclosed in U.S. Pat. No. 4,357,522, is a so-called self-cleaning or pyrolytic oven that has, in addition to the capability to cook and heat food, the capability to burn or vaporize the cooking residues or deposits left in the oven cavity. When operated to burn or vaporize the cooking residues or deposits left in the oven cavity, these self-cleaning or pyrolytic ovens such disclosed in U.S. Pat. No. 4,357,522 achieve temperatures higher than typical food preparation temperatures, often in the range of 750-930 degrees Fahrenheit (400-500 degrees Celsius), for the express purpose of burning or vaporizing the cooking residues left in the oven cavity. These higher temperatures in the range of 750-930 degrees Fahrenheit (400-500 degrees Celsius) are typically generated by one or more of the heating elements that normally serve to heat the oven cavity for food preparation purposes, such as, for example, a broiling element located internally to—i.e., within—the oven cavity or a bake heating element located externally to the oven cavity.
One type of commercially available self-cleaning or pyrolytic oven has an oven cavity whose interior surface, which delimits or defines the heated space, is comprised of a relatively smooth enamel material. It can happen during a self cleaning operation in such a commercially available self-cleaning or pyrolytic oven that the achieved higher temperatures in the range of 750-930 degrees Fahrenheit (400-500 degrees Celsius) result in an alteration in the appearance of the relatively smooth enamel material forming the interior surface of the oven cavity. This alteration is observed visually in the sense that the relatively smooth enamel material forming the interior surface of the oven cavity appears to have, after a number of self-cleaning operations have been performed, a very slightly different appearance as compared to its appearance before the self-cleaning operations were performed. To be sure, an alteration in the appearance of the relatively smooth enamel material forming the interior surface of an oven cavity of an oven does not invariably mean that the oven has been compromised in any way, as it is clear that the desired properties provided by such relatively smooth enamel material interior oven cavity surfaces, such as heat distribution and resistance to deposition of food residues thereon, are still provided by such relatively smooth enamel material interior oven cavity surfaces even though an alteration in the appearance of such can be visually observed. Nonetheless, in the interest of providing a greater capability to preserve or influence the appearance of relatively smooth enamel material interior oven cavity surfaces of ovens, it would be desirable to have an arrangement and a method for influencing the heat generated by a heating element located exteriorly to the wall of the oven cavity of an oven to thereby preserve or influence the appearance of an interior oven cavity surface of such an oven in a positive manner.
Moreover, it can be understood that a self-cleaning or pyrolytic oven may be subject to operational disadvantages if, due to the particular configuration of self-cleaning or pyrolytic oven, a heating element thereof torques, warps, or otherwise temporarily changes its shape during the self-cleaning process to an extent that a portion of the heating element touches or more closely approaches a portion of the structure that forms the oven cavity. For example, in one known configuration of a self-cleaning or pyrolytic oven, the structure that forms the oven cavity has a concave bottom shape in a center location and an exteriorly located heating element may be located within 1-2 millimeters of this concave bottom shaped structure in an unheated condition of the oven.
Also, it can be further understood that a user's acceptance of, or confidence in, the performance of a self-cleaning or pyrolytic oven may be negatively affected if there occurs an alteration in the appearance of the relatively smooth enamel material interior oven cavity surface to such a degree that there is discoloration, scorching, or even cracking of the surface.
As such, there remains a need to provide, with respect to self-cleaning ovens, an arrangement and a method for influencing the heat generated by a heating element located exteriorly to the wall of the oven cavity of such an oven to thereby preserve or influence the appearance of an interior oven cavity surface of such an oven in a positive manner.